// @(#)SimpleTrace.java   9/2002
// Copyright (c) 1998-2002, Distributed Real-time Computing Lab (DRCL) 
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package drcl.net.traffic;

import java.io.Reader;
import java.io.BufferedReader;
import drcl.comp.*;

/**
 * This class implements a simple trace component.
It recognizes the trace file in the following format:
<pre>
  &lt;time&gt;  &lt;packet_size&gt;
</pre>
And it ignores any line starting with "<code>#</code>".
 */
public class SimpleTrace extends TraceInput
{
  double lastTime, lastPeriodStart;

  public SimpleTrace()
  { super(); }

  public SimpleTrace(String id_)
  { super(id_); }

  BufferedReader breader;

  protected double setNextPacket(drcl.net.FooPacket nextpkt_) 
  {
    try{
      String line_ = null;
      if (breader == null)
        breader = reader instanceof BufferedReader?
          (BufferedReader)reader: new BufferedReader(reader);
      do {
        line_ = breader.readLine();
        if (line_ != null) line_ = line_.trim();
      }
      while (line_ != null && (line_.length() == 0 || line_.charAt(0) == '#'));

      if (line_ == null) {
        if (isLoopEnabled()) {
          try {
            reader.reset();
            lastPeriodStart += getLoopPeriod();
            if (lastPeriodStart < lastTime)
              lastPeriodStart = lastTime;
            do {
              line_ = breader.readLine();
              if (line_ != null) line_ = line_.trim();
            }
            while (line_ != null && (line_.length() == 0 || line_.charAt(0) == '#'));
            if (line_ == null)
              return Double.NaN;
          }
          catch (Exception e_) {
            drcl.Debug.error(this + " cannot reset the trace for looping");
            return Double.NaN;
          }
        }
        else
          return Double.NaN;
      }
      String[] elements_ = drcl.util.StringUtil.substrings(line_);
      nextpkt_.setPacketSize(Integer.parseInt(elements_[1]));
      lastTime = Double.valueOf(elements_[0]).doubleValue() + lastPeriodStart;
      return lastTime;
    }
    catch (Exception e_) {
      e_.printStackTrace();
      return Double.NaN;
    }
  }
  
  public void reset()
  {
    super.reset();
    lastTime = lastPeriodStart = 0.0;
    breader = null;
  }
  
  public void duplicate(Object source_)
  {
    super.duplicate(source_);
  }
  
  public String info()
  {
    return super.info()
      + "lastPeriodStart = " + lastPeriodStart + "\n"
      + "   lastTimeSent = " + lastTime + "\n";
  }
}
